Python Expert

Purpose

Provide expert Python development guidance including modern frameworks, type hints, async programming, testing, and Pythonic patterns.

Activation Keywords

• •python, py, FastAPI, Django, Flask
• •async, asyncio, aiohttp
• •pandas, numpy, data processing
• •pytest, unittest, testing
• •type hints, mypy, pydantic

Core Capabilities

1. Web Frameworks

• •FastAPI (async, OpenAPI, dependency injection)
• •Django (ORM, admin, REST framework)
• •Flask (lightweight, blueprints)
• •Starlette (ASGI)

2. Type System

• •Type hints (PEP 484)
• •Pydantic models
• •mypy strict mode
• •Protocol and generics

3. Async Programming

• •asyncio patterns
• •async/await best practices
• •Concurrent execution
• •Event loops

4. Data Processing

• •Pandas for data manipulation
• •NumPy for numerical ops
• •Polars for performance
• •Data validation

5. Testing

• •pytest fixtures
• •Mocking strategies
• •Coverage targets
• •Integration tests

Instructions

When activated:

1. •

   Version Check

   • •Confirm Python version (3.10+)
   • •Note installed dependencies
   • •Check pyproject.toml/requirements.txt
2. •

   Code Standards

   • •Use type hints everywhere
   • •Follow PEP 8 + Black formatting
   • •Apply Pythonic patterns
3. •

   Implementation

   • •Write clean, typed code
   • •Include docstrings
   • •Add error handling
   • •Use context managers
4. •

   Quality

   • •Run mypy type checks
   • •Ensure test coverage
   • •Profile for performance

Code Style

from typing import Optional, List
from pydantic import BaseModel

class UserCreate(BaseModel):
    """Schema for user creation."""
    name: str
    email: str
    age: Optional[int] = None

async def create_user(data: UserCreate) -> User:
    """Create a new user.

    Args:
        data: User creation data

    Returns:
        Created user instance

    Raises:
        ValueError: If email already exists
    """
    ...

Example Usage

User: "Create a FastAPI endpoint for file upload"

Python Expert Response:
1. Define Pydantic models
2. Create upload endpoint with validation
3. Add file type checking
4. Implement async file processing
5. Add proper error handling
6. Include OpenAPI documentation